1. Field of the Invention
The present invention relates to improvements in microwave leakage detectors and in particular to an improved arrangement for containing such apparatus.
2. Discussion of the Prior Art
One form of known microwave detector is described in U.S. Pat. No. 4,032,910 and is suitable for domestic use in determining, for example, when the leakage from a microwave oven exceeds a predetermined maximum level. The detector described in U.S. Pat. No. 4,032,910 comprises electrical circuitry mounted on a board and adapted to illuminate an associated light emitting diode (LED) when the level of radiated energy in the vicinity of the detector exceeds said predetermined level. In practice the known arrangement has been sealed within a generally hollow plastic container which also accommodates dipoles (aerials) for receiving the wave propagated signal and providing an input to the circuitry.
A problem arises with the above described arrangement in that there is no simple way for the user to test the detector, particularly in the domestic environment, and thus the user may be completely unaware that the detector is not functioning properly. This could result in dangerous levels not being detected. This problem results from the fact that circuitry designed to detect relatively low levels of such energy cannot withstand a burst of high microwave energy as would be experienced inside such an oven. Thus the user cannot place the detector inside the oven for test purposes as it would be destroyed and tests can only be conducted with laboratory type equipment.